Eulithoxenus mongolicus ( Uvarov, 1928 )

Korsunovskaya, Olga, 2024, Drymadusini katydids (Orthoptera: Tettigoniidae; Tettigoniinae): intraspecific variability-morphs or subspecies?, Zootaxa 5403 (1), pp. 42-50 : 43

Eulithoxenus mongolicus ( Uvarov, 1928)

( Figs 1 , 3G, H )

While alive, the insect had a bright blue abdomen and greyish-blue other parts of the body ( Fig.1A ). The post mortem color change led to the loss of the blue color, and as a result, the male’s head and pronotum became light brown, and the abdomen became black ( Fig. 1B, D ). In the original description of the species, B. Uvarov (1928) indicated that, according to the collector, living bush-crickets were greenish in color.

A thorough morphological study of our specimen and comparison with males of the type series showed significant similarities in the structure of the pronotum ( Fig. 1B–E ), cerci, supra-anal and subgenital plates ( Fig. 1H, I ), and revealed some differences. In particular, comparison with type and topotype specimens ( Fig. 1C, E, G, I, J ) showed that tegmina of the Tuvan bush-crickets are slightly larger in size, central part of the upper one is lighter ( Fig. 1F ), the lateral edges of the pronotum without a light border ( Fig. 1D ), and the titillators are slightly expanded in the apical part ( Fig. 1K ), The color of specimens of the type series is uniformly brownish ( Fig. 1C ). S. Storozhenko, who analyzed a large number of bush-crickets from both Mongolia and Tuva, identified them as E. mongolicus . He also gives a drawing of titillators with an expanded apical part ( Storozhenko, 2004, Fig. 305). In addition, in the redescription he indicates that the color of the abdomen of these katydids is black ( Storozhenko, 2004). Thus, their lifetime color could also have been blue. It is possible that under conditions of increased insolation, insects may develop protective adaptations, in particular, blue coloration of the integument, which allows them to absorb UV rays, protecting underlying tissues. Perhaps, this is precisely the phenomenon we encounter when analyzing E. mongolicus . It is known that in orthopteroids, blue, green, brown, yellow and even red colors can be provided by pigments from one group—tetrapyrroles ( Futahashi & Osanai-Futahashi, 2021). We believe that the specimen we caught in Tuva deserves to be separated into a special form— E. mongolicus forma caeruleum. Further research may make it possible to raise this infraspecific rank of the taxon to subspecific.

Material examined

Mongolia: 4 ♂ (type and topotypes) : foothills of Ikhé-Bogdo , Gobi Altai , Mongolia, 15–16. VIII. 1926, Kiritchenko leg.; 1 ♂ , Mongolia: Bajan Khong aimak, S slope, Ikh-Bogdo-Ula N Bajan-Gobi, 2200–2700 a. s. l., 7–8 VIII. 1969, M. Kozlov leg.; 1 ♂ : Russia: Southern Tuva, 35 km N village Erzin , 11.IX.1986, Korsunovskaya leg.

Figures

FIGURE 1. Habitus and details of body structure of Eulithoxenus mongolicus. A—habitus of E. mongolicus f. caeruleum; B— male of E. mongolicus f. caeruleum; C—male of E. mongolicus (holotype); D—male pronotum of E. mongolicus f. caeruleum, lateral view; E—same of E. mongolicus, holotype; F—left tegmen of E. mongolicus f. caeruleum, dorsal view; G—same of E. mongolicus (Mongolia); H—male supra-anal plate and cerci of E. mongolicus f. caeruleum; I—same of E. mongolicus, topotype; J—titillators of E. mongolicus, holotype; K—titillator of E. mongolicus f. caeruleum. Scale 5 mm (A, B, D, H, J, K), 1 mm (C, E, F, G, I, M, N), 500 µ (L, O, P).

FIGURE 3. Temporal pattern, frequency spectra of male calling songs and stridulatory files of E. mongolicus and L. miramae. A, B—oscillograms of calling song of E. mongolicus f. caeruleum; C—frequency spectrum of calling song of E. mongolicus f. caeruleum; D, E—oscillograms of calling song of L. miramae; F—frequency spectrum of calling song of L. miramae; G—stridulatory file of E. mongolicus (Mongolia); H—same of E. mongolicus f. caeruleum (Tuva); I—same of L. miramae (Uzbekistan). B, E—oscillograms at higher speed. Spectra are in linear scale. Scale bar: A, C—500 ms, B, D—50 ms; G—I— 500 µ. The temperature when recording sounds is given.